1
|
Jett S, Boneu C, Zarate C, Carlton C, Kodancha V, Nerattini M, Battista M, Pahlajani S, Williams S, Dyke JP, Mosconi L. Systematic review of 31P-magnetic resonance spectroscopy studies of brain high energy phosphates and membrane phospholipids in aging and Alzheimer's disease. Front Aging Neurosci 2023; 15:1183228. [PMID: 37273652 PMCID: PMC10232902 DOI: 10.3389/fnagi.2023.1183228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/02/2023] [Indexed: 06/06/2023] Open
Abstract
Many lines of evidence suggest that mitochondria have a central role in aging-related neurodegenerative diseases, such as Alzheimer's disease (AD). Mitochondrial dysfunction, cerebral energy dysmetabolism and oxidative damage increase with age, and are early event in AD pathophysiology and may precede amyloid beta (Aβ) plaques. In vivo probes of mitochondrial function and energy metabolism are therefore crucial to characterize the bioenergetic abnormalities underlying AD risk, and their relationship to pathophysiology and cognition. A majority of the research conducted in humans have used 18F-fluoro-deoxygluose (FDG) PET to image cerebral glucose metabolism (CMRglc), but key information regarding oxidative phosphorylation (OXPHOS), the process which generates 90% of the energy for the brain, cannot be assessed with this method. Thus, there is a crucial need for imaging tools to measure mitochondrial processes and OXPHOS in vivo in the human brain. 31Phosphorus-magnetic resonance spectroscopy (31P-MRS) is a non-invasive method which allows for the measurement of OXPHOS-related high-energy phosphates (HEP), including phosphocreatine (PCr), adenosine triphosphate (ATP), and inorganic phosphate (Pi), in addition to potential of hydrogen (pH), as well as components of phospholipid metabolism, such as phosphomonoesters (PMEs) and phosphodiesters (PDEs). Herein, we provide a systematic review of the existing literature utilizing the 31P-MRS methodology during the normal aging process and in patients with mild cognitive impairment (MCI) and AD, with an additional focus on individuals at risk for AD. We discuss the strengths and limitations of the technique, in addition to considering future directions toward validating the use of 31P-MRS measures as biomarkers for the early detection of AD.
Collapse
Affiliation(s)
- Steven Jett
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Boneu
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Zarate
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Caroline Carlton
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Vibha Kodancha
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Matilde Nerattini
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Michael Battista
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Silky Pahlajani
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Schantel Williams
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| |
Collapse
|
2
|
Gyanwali B, Shaik MA, Tan CS, Vrooman H, Venketasubramanian N, Chen C, Hilal S. Mixed-location cerebral microbleeds as a biomarker of neurodegeneration in a memory clinic population. Aging (Albany NY) 2019; 11:10581-10596. [PMID: 31767809 PMCID: PMC6914397 DOI: 10.18632/aging.102478] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/08/2019] [Indexed: 11/25/2022]
Abstract
Cerebral microbleeds (CMBs) in the lobar and deep locations are associated with two distinct pathologies: cerebral amyloid angiopathy and hypertensive arteriopathy. However, the role of mixed-location CMBs in neurodegeneration remains unexplored. We investigated the associations between strictly lobar, strictly deep and mixed-location CMBs with markers of neurodegeneration. This study recruited 477 patients from a memory clinic who underwent 3T MRI scans. CMBs were categorized into strictly lobar, strictly deep and mixed-location. Cortical thickness, white matter volume and subcortical structural volumes were quantified using Free-Surfer. Linear regression models were performed to assess the association between CMBs and cerebral atrophy, and the mean difference (β) and 95% confidence intervals (CIs) were reported. In the regression analyses, mixed-location CMBs were associated with smaller cortical thickness of limbic region [β= -0.01; 95% CI= -0.02, -0.00, p=0.007) as well as with smaller accumbens volume [β= -0.01; 95% CI= -0.02, -0.00, p=0.004) and presubiculum region of hippocampus [β= -0.01; 95% CI= -0.02, -0.00, p=0.002). Strictly lobar CMBs were associated with smaller total white matter volume [β= -0.03; 95% CI= -0.04, -0.01, p<0.001] and with region specific white matter volumes. The underlying mechanism requires further research and may involve shared mechanisms of vascular dysfunction and neurodegeneration.
Collapse
Affiliation(s)
- Bibek Gyanwali
- Memory Aging and Cognition Centre, National University Health System, Singapore.,Department of Pharmacology, National University of Singapore, Singapore
| | - Muhammad Amin Shaik
- Ageing Research Institute for Society and Education, Nanyang Technological University, Singapore
| | - Chuen Seng Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Henri Vrooman
- Departments of Radiology and Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Christopher Chen
- Memory Aging and Cognition Centre, National University Health System, Singapore.,Department of Pharmacology, National University of Singapore, Singapore
| | - Saima Hilal
- Memory Aging and Cognition Centre, National University Health System, Singapore.,Department of Pharmacology, National University of Singapore, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, Singapore.,Departments of Epidemiology and Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
3
|
Rijpma A, van der Graaf M, Meulenbroek O, Olde Rikkert MGM, Heerschap A. Altered brain high-energy phosphate metabolism in mild Alzheimer's disease: A 3-dimensional 31P MR spectroscopic imaging study. NEUROIMAGE-CLINICAL 2018; 18:254-261. [PMID: 29876246 PMCID: PMC5987799 DOI: 10.1016/j.nicl.2018.01.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 12/15/2017] [Accepted: 01/24/2018] [Indexed: 12/20/2022]
Abstract
In Alzheimer's disease (AD), defects in essential metabolic processes for energy supply and phospholipid membrane function have been implicated in the pathological process. However, post-mortem investigations are generally limited to late stage disease and prone to tissue decay artifacts. In vivo assessments of high energy phosphates, tissue pH and phospholipid metabolites are possible by phosphorus MR spectroscopy (31P–MRS), but so far only small studies, mostly focusing on single brain regions, have been performed. Therefore, we assessed phospholipid and energy metabolism in multiple brain regions of 31 early stage AD patients and 31 age- and gender-matched controls using 31P–MRS imaging. An increase of phosphocreatine (PCr) was found in AD patients compared with controls in the retrosplenial cortex, and both hippocampi, but not in the anterior cingulate cortex. While PCr/inorganic phosphate and pH were also increased in AD, no changes were found for phospholipid metabolites. This study showed that PCr levels are specifically increased in regions that show early degeneration in AD. Together with an increased pH, this indicates an altered energy metabolism in mild AD. Phosphocreatine and pH are increased in mild Alzheimer's disease. Phosphocreatine increase occurs in early affected brain regions. Brain energy metabolism may be altered in mild Alzheimer's disease. Phospholipid and energy metabolites as well as pH, differ across brain regions.
Collapse
Key Words
- 1H, proton
- 31P–MRS, phosphorus magnetic resonance spectroscopy
- AC, anterior commissure
- ACC, anterior cingulate cortex
- AD, Alzheimer's disease
- ADP, adenosine diphosphate
- ATP, adenosine triphosphate
- Alzheimer's disease
- CK, creatine kinase
- CSF, cerebrospinal fluid
- Cr, creatine
- Dementia
- Energy metabolism
- GM, grey matter
- GPCh, glycerophosphocholine
- GPEth, glycerophosphoethanolamine
- HL, left hippocampus
- HR, right hippocampus
- LS, least square
- MCI, mild cognitive impairment
- MMSE, Mini Mental State Examination
- MRSI, magnetic resonance spectroscopic imaging
- NAD(H), nicotinamide adenine dinucleotide
- OXPHOS, oxidative phosphorylation
- PC, posterior commissure
- PCh, phosphocholine
- PCr, phosphocreatine
- PDE, phosphodiesters
- PEth, phosphoethanolamine
- PME, phosphomonoesters
- Phospholipid metabolism
- Phosphorus magnetic resonance spectroscopic imaging
- Pi, inorganic phosphate
- ROI, region of interest
- RSC, retrosplenial cortex
- WM, white matter
Collapse
Affiliation(s)
- Anne Rijpma
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands.
| | - Marinette van der Graaf
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands; Department of Paediatrics, Radboud university medical center, Nijmegen, The Netherlands
| | - Olga Meulenbroek
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Marcel G M Olde Rikkert
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| |
Collapse
|
4
|
The medical food Souvenaid affects brain phospholipid metabolism in mild Alzheimer's disease: results from a randomized controlled trial. ALZHEIMERS RESEARCH & THERAPY 2017; 9:51. [PMID: 28747210 PMCID: PMC5530581 DOI: 10.1186/s13195-017-0286-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/10/2017] [Indexed: 11/21/2022]
Abstract
Background Synaptic dysfunction contributes to cognitive impairment in Alzheimer’s disease and may be countered by increased intake of nutrients that target brain phospholipid metabolism. In this study, we explored whether the medical food Souvenaid affects brain phospholipid metabolism in patients with Alzheimer’s disease. Methods Thirty-four drug-naive patients with mild Alzheimer’s disease (Mini Mental State Examination score ≥20) were enrolled in this exploratory, double-blind, randomized controlled study. Before and after 4-week intervention with Souvenaid or an isocaloric control product, phosphorus and proton magnetic resonance spectroscopy (MRS) was performed to assess surrogate measures of phospholipid synthesis and breakdown (phosphomonoesters [PME] and phosphodiesters [PDEs]), neural integrity (N-acetyl aspartate), gliosis (myo-inositol), and choline metabolism (choline-containing compounds [tCho]). The main outcome parameters were PME and PDE signal intensities and the PME/PDE ratio. Results MRS data from 33 patients (60–86 years old; 42% males; Souvenaid arm n = 16; control arm n = 17) were analyzed. PME/PDE and tCho were higher after 4 weeks of Souvenaid compared with control (PME/PDE least squares [LS] mean difference [95% CI] 0.18 [0.06–0.30], p = 0.005; tCho LS mean difference [95% CI] 0.01 [0.00–0.02], p = 0.019). No significant differences were observed in the other MRS outcome parameters. Conclusions MRS reveals that Souvenaid affects brain phospholipid metabolism in mild Alzheimer’s disease, in line with findings in preclinical studies. Trial registration Netherlands Trial Register, NTR3346. Registered on 13 March 2012. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0286-2) contains supplementary material, which is available to authorized users.
Collapse
|
5
|
Forlenza OV, Schaeffer EL, Gattaz WF. The role of phospholipase A2 in neuronal homeostasis and memory formation: implications for the pathogenesis of Alzheimer's disease. J Neural Transm (Vienna) 2006; 114:231-8. [PMID: 17131232 DOI: 10.1007/s00702-006-0597-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 10/30/2006] [Indexed: 11/28/2022]
Abstract
Phospholipase A(2) (PLA(2)) is a key enzyme in cerebral phospholipid metabolism. Preliminary post-mortem studies have shown that PLA(2) activity is decreased in frontal and parietal areas of the AD brain, which is in accordance with recent (31)P-Magnetic Resonance Spectroscopy evidence of reduced phospholipid turnover in the pre-frontal cortex of moderately demented AD patients. Such abnormality may also be observed in peripheral cells, and reduced PLA(2) activity in platelet membranes of AD patients, and correlates with the severity of dementia. In rat hippocampal slices, PLA(2) has been implicated in mechanisms of synaptic plasticity. In adult rats, the stereotaxic injection of PLA(2) inhibitors in the CA1 area of hippocampus impaired, in a dose-dependent manner, the formation of short- and long-term memory. Additionally, such inhibition resulted in a reduction of the fluidity of hippocampal membranes. In primary cultures of cortical and hippocampal neurons, the inhibition of PLA(2) precluded neurite outgrowth, and the sustained inhibition of the enzyme in mature cultures lead to loss of viability. Taken together, these findings reinforce the involvement of PLA(2) enzymes in neurodevelopment and neurodegeneration processes, and further suggest that reduced PLA(2) activity, probably reducing membrane phospholipids breakdown, may contribute to the memory impairment in AD.
Collapse
Affiliation(s)
- O V Forlenza
- Laboratory of Neuroscience, Department & Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | | |
Collapse
|
6
|
Forlenza OV, Wacker P, Nunes PV, Yacubian J, Castro CC, Otaduy MCG, Gattaz WF. Reduced phospholipid breakdown in Alzheimer's brains: a 31P spectroscopy study. Psychopharmacology (Berl) 2005; 180:359-65. [PMID: 15700180 DOI: 10.1007/s00213-005-2168-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 12/20/2004] [Indexed: 12/13/2022]
Abstract
BACKGROUND Abnormalities of membrane phospholipid metabolism have been described in Alzheimer's disease (AD). We investigated, with the aid of (31)P magnetic resonance spectroscopy, the in vivo intracerebral availability of phosphomonoesters (PME) and phosphodiesters (PDE) in patients with AD. METHODS Eighteen outpatients with mild or moderate probable AD and 16 nondemented elderly volunteers were assessed with the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) and its cognitive subscale of the CAMDEX schedule (CAMCOG). Scans were performed on a 1.5 T magnetic resonance imager addressing a 40-cm(3) voxel in the left prefrontal cortex. Main outcome measures were mean relative peak areas of PME and PDE, which provide an estimate of membrane phospholipid metabolism. RESULTS PME resonance and the PME/PDE ratio were increased in AD patients as compared to controls (p<0.05). PME was negatively correlated with global cognitive performance as shown by the Mini-Mental State Examination (r(s)=-0.36, p=0.05) and CAMCOG scores (r(s)=-0.49, p=0.007), as well as with discrete neuropsychological functions, namely, memory (r(s)=-0.53, p=0.004), visual perception (r(s)=-0.54, p=0.003), orientation (r(s)=-0.36, p=0.05), and abstract thinking (r(s)=-0.48, p=0.01). CONCLUSIONS We provide evidence of reduced membrane phospholipid breakdown in the prefrontal cortex of mild and moderately demented AD patients. These abnormalities correlate with neuropsychological deficits that are characteristic of AD.
Collapse
Affiliation(s)
- Orestes V Forlenza
- Laboratory of Neuroscience (LIM-27) Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovídio Pires de Campos 785, 05403-010, São Paulo, SP, Brazil
| | | | | | | | | | | | | |
Collapse
|
7
|
Hsu YY, Du AT, Schuff N, Weiner MW. Magnetic resonance imaging and magnetic resonance spectroscopy in dementias. J Geriatr Psychiatry Neurol 2001; 14:145-66. [PMID: 11563438 PMCID: PMC1857299 DOI: 10.1177/089198870101400308] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection of affected individuals, monitoring disease progression, and evaluation of therapeutic effect.
Collapse
Affiliation(s)
- Y Y Hsu
- Magnetic Resonance Unit, Department of Veterans Affairs Medical Center, San Francisco 94121, USA
| | | | | | | |
Collapse
|
8
|
Fein G, Di Sclafani V, Tanabe J, Cardenas V, Weiner MW, Jagust WJ, Reed BR, Norman D, Schuff N, Kusdra L, Greenfield T, Chui H. Hippocampal and cortical atrophy predict dementia in subcortical ischemic vascular disease. Neurology 2000; 55:1626-35. [PMID: 11113215 PMCID: PMC2733356 DOI: 10.1212/wnl.55.11.1626] [Citation(s) in RCA: 275] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The cause of dementia in subcortical ischemic vascular disease (SIVD) is controversial. OBJECTIVES To determine whether cognitive impairment in SIVD 1) correlates with measures of ischemic brain injury or brain atrophy, and/or 2) is due to concomitant AD. METHODS Volumetric MRI of the brain was performed in 1) elderly subjects with lacunes (L) and a spectrum of cognitive impairment-normal cognition (NC+L, n = 32), mild cognitive impairment (CI+L, n = 26), and dementia (D+L, n = 29); 2) a comparison group with probable AD (n = 28); and 3) a control group with normal cognition and no lacunes (NC). The authors examined the relationship between the severity of cognitive impairment and 1) volume, number, and location of lacunes; 2) volume of white matter signal hyperintensities (WMSH); and 3) measures of brain atrophy (i. e., hippocampal, cortical gray matter, and CSF volumes). RESULTS Among the three lacune groups, severity of cognitive impairment correlated with atrophy of the hippocampus and cortical gray matter, but not with any lacune measure. Although hippocampal atrophy was the best predictor of severity of cognitive impairment, there was evidence for a second, partially independent, atrophic process associated with ventricular dilation, cortical gray matter atrophy, and increase in WMSH. Eight autopsied SIVD cases showed variable severity of ischemic and neurofibrillary degeneration in the hippocampus, but no significant AD pathology in neocortex. The probable AD group gave evidence of only one atrophic process, reflected in the severity of hippocampal atrophy. Comparison of regional neocortical gray matter volumes showed sparing of the primary motor and visual cortices in the probable AD group, but relatively uniform atrophy in the D+L group. CONCLUSIONS Dementia in SIVD, as in AD, correlates best with hippocampal and cortical atrophy, rather than any measure of lacunes. In SIVD, unlike AD, there is evidence for partial independence between these two atrophic processes. Hippocampal atrophy may result from a mixture of ischemic and degenerative pathologies. The cause of diffuse cortical atrophy is not known, but may be partially indexed by the severity of WMSH.
Collapse
Affiliation(s)
- G Fein
- Neurobehavioral Research, Inc., San Francisco, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Moore CM, Frederick BB, Renshaw PF. Brain biochemistry using magnetic resonance spectroscopy: relevance to psychiatric illness in the elderly. J Geriatr Psychiatry Neurol 2000; 12:107-17. [PMID: 10593699 DOI: 10.1177/089198879901200304] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Magnetic resonance spectroscopy (MRS) allows for the noninvasive study of cerebral biochemistry. It has been used to investigate cerebral metabolic changes associated with mental illness in vivo and in vitro. In this review, we will discuss the application of MRS to psychiatric illness in the elderly. Following a brief description of the basic principles of MRS, the use of phosphorus (31P) and proton (1H) MRS to enable a better understanding of normal brain aging, dementia (Alzheimer's disease, multiple subcortical infarct dementia, Down syndrome, frontotemporal dementia, vascular dementia, age-associated memory impairment, and other dementias), major depression, and electroconvulsive therapy is detailed.
Collapse
Affiliation(s)
- C M Moore
- Brain Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA
| | | | | |
Collapse
|
10
|
Terwel D, Bothmer J, Wolf E, Meng F, Jolles J. Affected enzyme activities in Alzheimer's disease are sensitive to antemortem hypoxia. J Neurol Sci 1998; 161:47-56. [PMID: 9879681 DOI: 10.1016/s0022-510x(98)00240-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Many enzyme activities in Alzheimer's disease (AD) are changed. Some of these enzyme activities are related to certain neurotransmitter systems. Enzymes in the brain can also be sensitive to antemortem hypoxia. In the present study it was determined if enzyme activities that are altered in AD are also subject to alteration by antemortem hypoxia. As an indicator of antemortem hypoxia brain lactate concentration was used. Enzyme activities measured were those of prolyl endopeptidase (PE), aminopeptidase (AP), phosphatidylinositol (PI) kinase, phosphatidylinositol phosphate kinase, alpha-ketoglutarate dehydrogenase (alpha-KGDH), choline acetyltransferase and beta-glucuronidase. All of these enzyme activities have been measured in AD patients before and several of them have been found to be decreased. In accordance with previous findings, PE, alpha-KGDH and ChAT activities were reduced in AD patients. PI kinase and beta-glucuronidase activities, however, were not reduced, contrary to previous findings. All enzyme activities, except that of beta-glucuronidase, correlated with brain lactate concentration, suggesting that antemortem hypoxia has a major influence on the activity of enzymes in the brain. PE, AP, alpha-KGDH and ChAT activities were still different between AD and control samples when these were matched for lactate concentration. The enzyme activities that were changed in AD were also significantly correlated with lactate concentration, an indicator of antemortem hypoxia, in brain specimens. This suggests that antemortem hypoxia and AD have some factor in common that may be responsible for changes in enzyme activities. Since both PE and alpha-KGDH are known to be sensitive to oxidative stress this factor could be oxidative stress.
Collapse
Affiliation(s)
- D Terwel
- European Graduate School of Neuroscience (Euron), Department of Psychiatry and Neuropsychology, Maastricht University, The Netherlands.
| | | | | | | | | |
Collapse
|
11
|
Mason GF, Chu WJ, Vaughan JT, Ponder SL, Twieg DB, Adams D, Hetherington HP. Evaluation of 31P metabolite differences in human cerebral gray and white matter. Magn Reson Med 1998; 39:346-53. [PMID: 9498589 DOI: 10.1002/mrm.1910390303] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
31P NMR is commonly used to study brain energetics in health and disease. Due to sensitivity constraints, the NMR measurements are typically made in volumes that do not contain pure gray or white matter. For accurate evaluation of abnormalities in brain metabolite levels, it is necessary to consider the differences in normal levels of 31P metabolites in gray and white matter. In this study, voxels from a three-dimensional spectroscopic image acquisition were analyzed for their dependence on tissue type to assess differences in metabolite levels between gray and white matter. Specifically, gray matter was found to have significantly higher ratios of phosphocreatine (PCr) to gamma-ATP and PCr to the total 31P metabolite signal, whereas pH and the ratio of PCr to inorganic phosphate (Pi) were found to differ insignificantly between gray and white matter. Thus, tissue type can be an important factor to consider for alterations in bioenergetics by 31P NMR spectroscopic studies of the brain.
Collapse
Affiliation(s)
- G F Mason
- Department of Medicine, Center for Nuclear Imaging Research, University of Alabama at Birmingham, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Klunk WE, Xu C, Panchalingam K, McClure RJ, Pettegrew JW. Quantitative 1H and 31P MRS of PCA extracts of postmortem Alzheimer's disease brain. Neurobiol Aging 1996; 17:349-57. [PMID: 8725895 DOI: 10.1016/0197-4580(96)00035-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Several previous studies have shown metabolic abnormalities in perchloric acid extracts of postmortem Alzheimer's disease (AD) brain by both proton (1H) and phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In all of these studies the results were expressed in relative terms, in units of mol percent. The results of this study, expressed in the absolute units of mumol/g wet weight, verify the previous 1H and 31P MRS studies. Absolute increases were found for myo-inositol, aspartate, L-glutamate, alanine, phosphocholine, and the phosphodiesters,. Absolute decreases were found for phosphoethanolamine and N-acetyl-l-aspartate. Many of these changes also were observed in non-AD dementia brain extracts, but changes in myo-inositol, inositol-l-phosphate, aspartate, and L-glutamate appeared to be more specific for AD in extracts of many brain areas. These results suggest that compounds related to membrane degradation and excitatory neuro-transmission increase in Alzheimer's disease while compounds related to neuronal integrity and inhibitory neurotransmission are decreased.
Collapse
Affiliation(s)
- W E Klunk
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA 15261, USA
| | | | | | | | | |
Collapse
|
13
|
MacKay S, Meyerhoff DJ, Constans JM, Norman D, Fein G, Weiner MW. Regional gray and white matter metabolite differences in subjects with AD, with subcortical ischemic vascular dementia, and elderly controls with 1H magnetic resonance spectroscopic imaging. ARCHIVES OF NEUROLOGY 1996; 53:167-74. [PMID: 8639067 PMCID: PMC2733342 DOI: 10.1001/archneur.1996.00550020079018] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To use 1H magnetic resonance spectroscopic imaging to study differences in neuron density (N-acetylaspartate [NAA]), membrane phospholipid metabolites (choline [Cho]), and creatine-containing metabolites (creatine plus phosphocreatine [Cr]) in subjects with Alzheimer's disease (AD), with subcortical ischemic vascular dementia (SIVD), and elderly controls. DESIGN Cross-sectional, between groups. SETTING A Veterans Affairs medical center and university memory clinic. PARTICIPANTS Forty elderly subjects with AD (n = 14), with SIVD (n = 8), and elderly controls (n = 18). MAIN OUTCOME MEASURES We used 1H magnetic resonance spectroscopic imaging to acquire spectra from a 80 x 100 x 17-mm volume superior to the lateral ventricles. Spectra were analyzed from voxels in anterior, medial, and posterior gray and white matter using nuclear magnetic resonance-1 and the results were compared between groups using repeated measures analysis of variance (ANOVA), Tukey's test, and individual Student's t tests. RESULTS Using ANOVA, significantly lower levels of NAA/Cho and NAA/Cr and significantly higher levels of Cho/Cr were observed across both gray and white matter voxels in subjects with AD. Using individual Student's t tests, a significantly lower level of NAA/Cho and a higher level of Cho/Cr were observed in the posterior gray matter in subjects with AD. Using ANOVA in subjects with SIVD, significantly lower gray and white matter NAA/Cr levels were observed. Using Tukey's test, the NAA/Cr level was significantly lower in frontal white matter voxels in subjects with SIVD compared with controls. CONCLUSIONS Our findings in subjects with AD suggest neuron loss in gray matter, axon loss in white matter, and altered Cho metabolism in posterior brain regions. Our findings in subjects with SIVD are consistent with higher levels of creatine-containing metabolites and/or lower levels of NAA in frontal white matter.
Collapse
Affiliation(s)
- S MacKay
- Magnetic Resonance Spectroscopy Unit, Department of Veterans Affairs Medical Center, San Francisco, USA
| | | | | | | | | | | |
Collapse
|
14
|
Gilberto González R. Molecular and functional magnetic resonance neuroimaging for the study of dementia. Ann N Y Acad Sci 1996; 777:37-48. [PMID: 8624115 DOI: 10.1111/j.1749-6632.1996.tb34399.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The living brain's structure, function, and underlying chemistry are increasingly being revealed in sharpened detail by the extraordinary evolution of magnetic resonance (MR) technology. Recent years have ushered in a wealth of new information about neurophysiology and pathological states owing to such technologies as functional MR imaging (fMRI), MR spectroscopy (MRS), and MR spectroscopic imaging (MRSI). These advances are of substantial benefit in the study of the dementias, especially Alzheimer's disease (AD). One primary objective of our laboratory at the Massachusetts General Hospital NMR Center is to utilize these extant and emerging MR technologies to further understanding of the human brain as it undergoes assault by AD. Our approach is guided by the belief that the pathological states observed in the AD brain must be accompanied by structural, chemical and/or physiological changes that can be made visible in an in vivo MR study. Quantitative measurements by MRI medical temporal lobe structures have been shown to be abnormal by several groups including our own. This use of MRI will be reviewed by others. In this paper, I will review recent advances in the application of MR for the study of chemical and functional brain abnormalities in dementia, and in particular to the investigation of AD.
Collapse
|
15
|
Smith CD. Quantitative computed tomography and magnetic resonance imaging in aging and Alzheimer's disease. A review. J Neuroimaging 1996; 6:44-53. [PMID: 8555663 DOI: 10.1111/jon19966144] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In recent aging research, quantitative techniques have been used to overcome limitations of qualitative interpretation of magnetic resonance and computed tomographic imaging. The purpose of this review is to summarize imaging results emphasizing quantitative studies using these two modalities in human aging. Magnetic resonance spectroscopy is viewed as an extension of imaging, and results of in vivo spectroscopic studies are included. Because Alzheimer's disease (AD) is closely related to aging, a discussion of quantitative imaging techniques that may distinguish normal elderly from patients with AD is included.
Collapse
Affiliation(s)
- C D Smith
- Department of Neurology, University of Kentucky College of Medicine, Lexington 40536, USA
| |
Collapse
|
16
|
Smith CD, Pettigrew LC, Avison MJ, Kirsch JE, Tinkhtman AJ, Schmitt FA, Wermeling DP, Wekstein DR, Markesberry WR. Frontal lobe phosphorus metabolism and neuropsychological function in aging and in Alzheimer's disease. Ann Neurol 1995; 38:194-201. [PMID: 7654066 DOI: 10.1002/ana.410380211] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
31P Magnetic resonance spectroscopy of the frontal lobe was performed in 17 patients with Alzheimer's disease (AD), 8 elderly controls (EC), and 17 young controls (YC). The phosphocreatine/inorganic phosphate (PCr/Pi) ratio in AD (2.32 +/- 0.26 SD) was significantly lower than in EC (2.65 +/- 0.41). In AD patients, a correlation was observed between the PCr/Pi ratio and the dementia rating scale (r = -0.50, p = 0.04). A significant positive correlation between PCr/Pi ratio and age was observed in both AD (r = 0.67, p = 0.003) and YC (r = 0.63, p = 0.006) groups, however, suggesting caution in interpretation of this ratio in AD. We did not find differences between AD, EC, or YC in any other spectroscopic measure. A significant sex difference in the phosphomonoester/phosphodiester ratio (PME/PDE) ratio was observed in AD brain. Females had a lower PME/PDE ratio than males.
Collapse
Affiliation(s)
- C D Smith
- Magnetic Resonanance Imaging and Spectroscopy Center, University of Kentucky College of Medicine, Lexington 40536, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Passe TJ, Charles HC, Rajagopalan P, Krishnan KR. Nuclear magnetic resonance spectroscopy: a review of neuropsychiatric applications. Prog Neuropsychopharmacol Biol Psychiatry 1995; 19:541-63. [PMID: 8588055 DOI: 10.1016/0278-5846(95)00101-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. Magnetic resonance spectroscopy (MRS) is a powerful new neuropsychiatric research tool which allows for the noninvasive investigation of in vivo biochemistry. This review focuses on the recent applications of MRS to in vivo neuropsychiatric research. 2. The history of MRS as it has progressed from an in vitro method of biochemical analysis to its current in vivo research uses is presented. 3. A brief overview of the physical principles of MRS, including methods for spectral localization, is discussed. 4. Applications of the different MRS modalities (1H, 31P, 19F, 7Li, 13C and 23Na) to various neuropsychiatric disorders such as Alzheimer's disease, schizophrenia, affective disorders, acquired immunodeficiency disease, etc. are reviewed. The study of both fluorinated neuroleptics and the antidepressant fluoxetine using 19F MRS are discussed in greater detail. 5. Finally, potential future neuropsychiatric applications of MRS and specifically 19F MRS are presented.
Collapse
Affiliation(s)
- T J Passe
- Department of Psychiatry, Duke University Medical Center, Durham, NC, USA
| | | | | | | |
Collapse
|